JPH01142231A - Fuel feeding device and its control method - Google Patents

Abstract

PURPOSE:To allow the fuel injection without using an injector and attain the low cost by continuously injecting fuel into an intake pipe through an injection nozzle and adjusting the pressure of the fuel fed to this injection nozzle via a fuel pressure regulator based on the intake air quantity. CONSTITUTION:The fuel in a fuel tank 10 is pumped out by a fuel pump 11 and fed to an injection nozzle 14 fitted to an intake pipe 2 via a filter 12 and a fuel pressure regulator 13 to constitute a fuel feeding means. The high-pressure air from an air pump 15 is fed to an air solenoid 17 connected to an air regulator 16 and the injection nozzle 14 to constitute an air feeding means. The fuel pressure regulator 13 and the air solenoid 17 are controlled by a computer 18 based on the output signals of an intake air temperature sensor 3, an intake air pressure sensor 4, a water temperature sensor 5, a throttle position sensor and an air-fuel ratio sensor 9, and the fuel injection of the preset quantity is performed at the preset timing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel supply system for an internal combustion engine for an automobile and a control method thereof.

(Prior Art) With the improvement in performance of engines in recent years, the number of vehicles equipped with electronic fuel injection systems, especially multi-point injection systems, is rapidly increasing.

A conventional general multi-point injection system is the one described in Japanese Patent Publication No. 55-574. This multi-point injection system calculates an injector drive pattern from a basic injection amount map on a computer based on the amount of intake air detected by an air flow meter. (Duty.

By controlling the engine to maintain the stoichiometric air-fuel ratio in all operating ranges, the engine can be controlled to maintain the stoichiometric air-fuel ratio in all operating ranges, achieving both fuel efficiency and exhaust gas purification. It was obvious.

(Problems to be Solved by the Invention) However, when configuring the conventional multi-point injection system as described above, the components of the system are more expensive than the carburetor type, and among them, the expensive injector has a large number of cylinders. In addition, a separate dedicated injector is required to improve low-temperature startability, which increases the number of components, resulting in extremely high costs and complicated control logic.

For this reason, single-point injection systems have been developed that are close to carburetors in cost and multi-point injection systems in terms of performance, but even this single-point injection system requires injectors for main and cold start. , the objective of reducing costs can be achieved.

Furthermore, because fuel is injected using the throttle body, there are problems with poor distribution, such as delays in fuel supply during transient periods, and performance has not yet reached a satisfactory level.

This invention was made to solve the problems in conventional fuel supply devices as described above. In other words, the present invention can reduce the cost of the product, and
It is an object of the present invention to provide a fuel supply device and a control method thereof that can improve fuel atomization performance and fuel distribution performance at low temperatures or under light load during idling.

(Means for Solving the Problems) In order to achieve the above object, a fuel supply device according to the present invention includes an injection nozzle that is attached to an intake pipe of an engine and continuously injects fuel supplied from a fuel pump into the intake pipe. ,
A fuel pressure regulator connected between the injection nozzle and the fuel pump, an engine intake air amount detection means, and a computer that outputs a control signal to the fuel pressure regulator based on a detection signal from the intake air amount detection means. It is characterized by the fact that it is equipped with

A second aspect of the fuel supply device according to the present invention includes an injection nozzle that is attached to an intake pipe of an engine and continuously injects fuel supplied from a fuel pump into the intake pipe, and a fuel supply device that is connected between the injection nozzle and the fuel pump. an air pump that supplies air to the injection nozzle; and an air solenoid that is connected between the air pump and the injection nozzle and that controls the amount of air supplied to the injection nozzle.

A control signal is output to the fuel pressure regulator and the air solenoid based on detection signals from the engine intake air amount detection means, the engine warm-up state detection means, and the intake air amount detection means. It is characterized by being equipped with a computer that outputs a control signal to the air solenoid based on the detection signal.

Further, there is a method for controlling a fuel supply device according to the present invention.

An injection nozzle is attached to the intake pipe of the engine, fuel is continuously injected into the intake pipe, a fuel pressure regulator is connected between the injection nozzle and the fuel pump, and the amount of air taken into the engine is detected by an intake air amount detection means. The present invention is characterized in that fuel pressure regulation by the fuel pressure regulator is controlled based on the detected intake air amount.

And the second aspect of the control method according to the present invention is as follows.

An injection nozzle is attached to the intake pipe of the engine, fuel is continuously injected into the intake pipe, a fuel pressure regulator is connected between the injection nozzle and the fuel pump, and the amount of air taken into the engine is detected by an intake air amount detection means. , controls the fuel pressure adjustment by the fuel pressure regulator based on the detected intake air amount, connects an air pump to the injection nozzle via an air solenoid, detects the engine warm-up state, and controls the detected engine warm-up state. The present invention is characterized in that the supply of air to the injection nozzle by the air solenoid is duty-controlled based on the machine state and the detected intake air amount.

(Function) In the fuel supply device according to the first aspect of the present invention, the fuel supplied by the fuel pump from the injection nozzle is continuously injected into the intake pipe of the engine, and the pressure of the fuel supplied to the injection nozzle is equal to The pressure is regulated by a computer driving and controlling a fuel pressure regulator based on the intake air amount of the engine detected by the air amount detection means.

Furthermore, in addition to the fuel pressure control according to the first aspect, when the fuel supply device according to the second aspect of the present invention determines that the engine will perform a cold start based on the detection by the warm-up state detection means, The computer controls the duty of the air solenoid to supplementally supply compressed air to the injection nozzle to promote atomization of the fuel. In addition, if the computer determines that the engine is idling based on the detected intake air amount of the engine, it similarly controls the duty of the air solenoid to supplementally supply compressed air to the injection nozzle, thereby reducing fuel particles. promote the development of

The control method according to the first aspect of the present invention eliminates the need to control injection timing by supplying fuel by continuous injection using an injection nozzle without using an injector, and the amount of fuel supplied depends on the amount of intake air to the engine. The fuel pressure to the injection nozzle is controlled based on the pressure.

Further, there is a control method according to a second aspect of the present invention.

In addition to the control method in the first aspect described above, by controlling the air solenoid on a duty basis, compressed air is supplementarily supplied to the injection nozzle when the engine is started at low temperature or when idling, thereby reducing atomization during fuel injection. Facilitate. This eliminates the need for a dedicated injector for low-temperature starting.

(Example) The present invention will be described in more detail below based on an example shown in one drawing.

FIG. 1 shows an embodiment of a fuel supply device according to the present invention, and this fuel supply device includes detection means for detecting intake air amount, warm-up state, air-fuel ratio, etc., fuel supply means, It consists of a supply means and a computer for controlling these fuel supply means and air supply means.

The detection means includes an intake temperature sensor 3 and an intake pressure sensor 4 attached to the intake pipe 2 of the engine 1. Water temperature sensor 5 attached to the cooler of the engine 1 Throttle position sensor 7 attached to the throttle valve 6 in the intake pipe 2
and an air-fuel ratio sensor 9 attached to the exhaust pipe 8 of the engine 1.

The fuel supply means includes a fuel tank IO, a fuel pump It, and a fuel filter 12. It consists of a fuel pressure regulator 3 and an injection nozzle 14 attached to the intake pipe 2. In addition, the air supply means is an air pump 15.
．． It consists of an air solenoid 17 connected to an air regulator 1B and an injection nozzle 14.

The computer 18 also includes an intake air temperature sensor 3. Intake pressure sensor 4. A water temperature sensor 5, a throttle position sensor 7, and an air-fuel ratio sensor 9 are connected, and each sensor outputs a detection signal (T, P, T
.

The fuel regulator 13 has a structure as shown in FIG.
is supplied to the injection nozzle 14 from there. and valve case 1
The fuel pressure in 3c and the spring 13d are connected to the diaphragm 1.
The distance between the valve 13f and the valve seat 13g changes depending on the balance between the fuel pressure and the spring 13d.
The fuel pressure supplied to the jet nozzle 14 is regulated by adjusting the amount of fuel recirculated from the jet nozzle 14. Further, this fuel regulator 13 has a built-in step motor 13A, and the rotation of the rotor 13i of this step motor 13A causes the shaft 13j to move forward and backward in the axial direction, and by changing the pressing force of the spring 13d on the holder 13, the load can be adjusted. The fuel pressure can be controlled as desired. .

As shown in FIG. 3, the jet nozzle 14 has a fuel passage 14A connected to the fuel regulator 13 and an air passage 14B connected to the air solenoid 17, and the axis of the air nozzle 14b is aligned with that of the fuel nozzle 14a. It is formed to intersect with the axis at a predetermined angle θ. As shown in FIG. 4, one or more injection nozzles 14 are attached to the wall of the intake pipe 2 on the upstream side of the throttle valve 6 to continuously inject fuel into the intake pipe 2. There is. It is preferable that the intersection angle θ of the axes of the air nozzle 14b and the fuel nozzle +4a is 30″, and that the air injection axis α of the air nozzle 14b is directed toward the end of the throttle valve 6.

The computer 18 includes an intake air amount detection means, that is, an intake air temperature sensor 3. Intake pressure sensor 4. A detection signal (TA) is input from a throttle position sensor 7 and an engine speed sensor (not shown).

P, T, Ne), the intake air amount N h of the engine 1, that is, the engine load is calculated, and the amount of fuel to be injected is determined.

FIG. 5 shows the fuel pressure control map in the computer 18, and the computer 18 uses this map α.
Alternatively, the fuel pressure is determined based on the intake air amount of the engine 1 according to β, and an application pulse is output to the fuel pressure regulator 13 according to the basic characteristic diagram of the fuel pressure regulator shown in FIG. The step motor 13A of the fuel pressure regulator 13 is pulse-driven by the applied pulse from the computer 18, and the pressing force of the spring 13d is adjusted, thereby regulating the fuel pressure to a predetermined value.

Further, the computer 18 detects the air solenoid 17 according to the map γ shown in FIG.
The air solenoid 17 is duty-controlled by outputting a control signal to the air solenoid 17. Judging from the intake air amount detected by the intake air amount detection means, when the engine 1 is in an idling state, the computer 18 outputs a control signal to the air solenoid 17 to control the duty as in the case of starting at a low temperature. do.

The air solenoid 17 is connected to the computer 18 as described above.
The compressed air sent from the air pump 15 via the regulator 1B is duty-controlled and supplied to the injection nozzle 14 according to the duty control signal from the air pump 15. In the injection nozzle 14, the fuel is atomized using compressed air according to the characteristics shown in the basic atomization characteristic diagram of fuel shown in FIG.

To further explain the control method for the fuel supply system as described above based on the flowchart shown in FIG. 9, the computer 8 starts the engine (a) reads each parameter based on the detection signal from the latter sensor (b)
.

Next, compare the engine cooling water temperature (c).

When the temperature is below a predetermined temperature (15° C. in this embodiment) (d), that is, when the engine is started at a low temperature.

Drive the air pump I5 e) and the air solenoid 17
The duty control is controlled to supply compressed air to the injection nozzle 14, and the fuel pressure regulator 3 is controlled according to the map β in FIG.
The fuel pressure to the injection nozzle 14 is regulated by pulse control according to (f).

Further, the computer 8 further calculates the air-fuel ratio λ1 of the engine 1 based on the detection signal λ from the air-fuel ratio sensor 9g), and if this air-fuel ratio λ is λ1'', 1 (h), it remains unchanged according to the map β. Continue to control, but λ1″,
If it is not 1, the map β is corrected (i) and the air-fuel ratio λ1
is controlled so that it becomes λ1'', 1.

If the engine cooling water temperature is above the predetermined temperature (
In j), the computer 18 does not drive the air pump I5 and determines whether or not it is in an idling state from the ninth intake air amount (engine load) (k) L. If it is in an idling state (in () The air pump 15 is driven (e) in the same way as in the case of low-temperature starting, and the fuel pressure control by the map □β and the duty control of the air solenoid 17 are performed.Furthermore, when the engine l is not in an idling state (m), In this case, only the fuel pressure regulator 3 is controlled according to the map α without driving the air pump 15 (o) L, and the pressure of fuel to the jet nozzle 14 is regulated.

Further, the computer 8 calculates the air-fuel ratio λ of the engine l based on the detection signal λ from the air-fuel ratio sensor 9 (p), and when this air-fuel ratio λ1 is λ1'', 1 (q)
control continues according to the map α, but λ1″
, is not 1 (r), the map α is corrected (S) and the air-fuel ratio λ1 is controlled to become λ1', 1.

In the above embodiment, the intersection angle θ of the axes of the air nozzle 14b and the fuel nozzle 14a is set to 30'', and the air injection axis The fuel is injected into the part of the valve where the flow velocity is highest, resulting in the most efficient fuel atomization and distribution.

(Effects of the Invention) As described above, according to the present invention, it is possible to reduce the cost of the product because no injector is used, and the fuel supply is continuously injected by the injection nozzle, and the fuel pressure is regulated by the fuel pressure regulator. This greatly simplifies the control logic. In addition, in a device and control method that supplementally supplies compressed air to the injection nozzle by duty-controlling the air solenoid during cold starting or idling, it is possible to promote atomization of fuel during low engine load, and to drive the engine stably. This also eliminates the need for an injector for low-temperature starting, making it possible to further reduce the cost of 811 products.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a side sectional view showing a fuel pressure regulator in the same embodiment, Fig. 3 is a side sectional view showing an injection nozzle in the same embodiment, and Fig. m4 is a side sectional view showing an injection nozzle in the same embodiment. Figure 5 is a map for fuel pressure control, Figure 6 is a characteristic line diagram showing the relationship between the application in the fuel pressure regulator, pulses and fuel pressure, and Figure 7 is a side sectional view showing the installation status of the injection nozzle. FIG. 8 is a map for solenoid duty control, a characteristic diagram showing the relationship between air solenoid duty control and fuel atomization, and FIG. 9 is a flowchart showing the control method according to the present invention. 1... Engine 2... Intake pipe 3... Intake temperature sensor 4... Intake pressure sensor 5... Water temperature sensor 6... Throttle valve 7... Throttle position sensor 11... Fuel pump 13...Fuel pressure regulator 14...Injection nozzle 15...Air pump I7...Air solenoid 18...Computer Applicant Aisin Seiki Co., Ltd. Agent Patent attorney Asami Kato (1 other person) H2 Diagram 1 Figure 3 Figure 5 Figure 6 □ Applied pulse Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. An injection nozzle attached to an engine intake pipe that continuously injects fuel supplied from a fuel pump into the intake pipe, and a fuel pressure regulator connected between the injection nozzle and the fuel pump; A fuel supply device comprising an engine intake air amount detection means and a computer that outputs a control signal to the fuel pressure regulator based on a detection signal from the intake air amount detection means. 2. An injection nozzle attached to the intake pipe of the engine that continuously injects fuel supplied from the fuel pump into the intake pipe, a fuel pressure regulator connected between the injection nozzle and the fuel pump, and a supply of air to the injection nozzle. an air pump connected between the air pump and the injection nozzle to control the duty of the amount of air supplied to the injection nozzle; an engine intake air amount detection means; an engine warm-up state detection means; A computer is provided that outputs a control signal to the fuel pressure regulator and the air solenoid based on the detection signal from the air amount detection means, and outputs a control signal to the air solenoid based on the detection signal from the warm-up state detection means. A fuel supply device featuring: 3. Attach an injection nozzle to the intake pipe of the engine to continuously inject fuel into the intake pipe, connect a fuel pressure regulator between the injection nozzle and the fuel pump, and use an intake air amount detection means to measure the amount of air taken into the engine. A method for controlling a fuel supply device, comprising: detecting the amount of intake air, and controlling the regulation of fuel pressure by the fuel pressure regulator based on the detected amount of intake air. 4. Attach an injection nozzle to the intake pipe of the engine to continuously inject fuel into the intake pipe, connect a fuel pressure regulator between the injection nozzle and the fuel pump, and use an intake air amount detection means to measure the amount of air taken into the engine. control the fuel pressure regulation by the fuel pressure regulator based on the detected intake air amount, connect an air pump to the injection nozzle via an air solenoid, detect the warm-up state of the engine, and control the fuel pressure regulation by the fuel pressure regulator based on the detected intake air amount. 1. A method of controlling a fuel supply device, comprising duty-controlling the supply of air to an injection nozzle by an air solenoid based on the warm-up state of the fuel supply device and the detected intake air amount.